Dentin is the substance between enamel or cementum and the pulp chamber. It is secreted by the odontoblasts of the dental pulp. The formation of dentin is known as dentinogenesis. The porous, yellow-hued material is made up of 70% inorganic materials, 20% organic materials, and 10% water by weight.
Medical Definition of metaplasia. 1  1: transformation of one tissue into another metaplasia of cartilage into bone. 2  2: abnormal replacement of cells of one type by cells of another.
Intestinal metaplasia of the gastric mucosa is an intermediate precancerous gastric lesion in the gastric cancer cascade from chronic gastritis and atrophy to dysplasia and adenocarcinoma. Although the risk of gastric cancer is increased in patients with intestinal metaplasia, the absolute risk is low.